Dear Jeremy,
Thank you for your comment
<http://lists.w3.org/Archives/Public/public-owl-comments/
2009Jan/0051.html>
on the OWL 2 Web Ontology Language last call drafts.
We will deal with your specific comments regarding the various
documents in a separate email. In this email we will address your
more general remarks regarding motivation. In particular, you claim
that "The rationale document (and the design) has not taken into
account the cost of new features particularly to those who do not
need them". We note, however, that the story you use to illustrate
this claim applies equally well to OWL DL and OWL Full and to OWL1
with OWL Lite. For syntax, one could have ontologies published in
Turtle, NTriples, Manchester Syntax, etc. Furthermore, one could
point to extensions like Protege's extensions for QCRs and user
defined datatypes and, for that matter, OWL 1.1 and even current
versions of OWL.
Thus, we do not believe that the story gives new information or a new
perspective. One of the goals of OWL 2 from the beginning was to
reduce or eliminate, as much as possible, these costs by producing a
standard new version to converge on. We believe the overall
advantages and, especially, the new clarity of the specification will
make it easier for tool developers to cope with real world ontologies
and for new tool developers to enter the market. Furthermore, the
working group has continually worked to mitigate the transition
costs. OWL 2 deliberately avoids radical new features (such as non-
monotonic features, or an entirely new, stratified metamodeling
system, or fuzzy extensions). Even features that are well understood
and have strong utility and demand were dropped or weakened in
response to the sorts of analyses you ask for, e.g., property punning
or required n-ary data predicates.
Returning to the motivation for new language features, the New
Features and Rationale document (NF&R) [1] is being extended to
better document the motivation for the new features of OWL 2. We
should also mention that NF&R should be read in conjunction with the
OWL Use Cases and Requirements document [2], which already motivates
some of these new features, e.g., extended annotations. The make up
of the OWL working group is indicative of broad support for OWL 2,
not just from academia but also from industry, and we also received
many supportive comments in response to the call for review (see
[3]). Finally, your own comment expresses support for several of the
new features, including qualified cardinality constraints, property
chain inclusion axioms, (unary) datatypes, annotations and profiles.
Finally, you questioned the role of OWLED and its representativeness
w.r.t. the OWL community. The current wording of the Overview of the
New Features and Requirements mentions several underpinnings of the
new features of OWL 2. Only part of this experience came through the
OWLED workshops from 2005, 2006, 2007, and 2008DC, and only part of
that influenced the OWL member submission. There is desire for the
new features of OWL 2, and implementation experience as well. The
long-term business viability of OWL 2 remains to be determined, of
course, but the working group believes that there is sufficient
evidence to proceed.
In view of the above, the OWL WG does not intend to make any changes
to the design of OWL 2 in response to your comment.
[1] http://www.w3.org/2007/OWL/wiki/New_Features_and_Rationale
[2] http://www.w3.org/TR/webont-req/
[3] http://www.w3.org/2007/OWL/wiki/Support
Please acknowledge receipt of this email to <mailto:public-owl-
comments@w3.org> (replying to this email should suffice). In your
acknowledgment please let us know whether or not you are satisfied
with the working group's response to your comment.
Regards,
Ian Horrocks
on behalf of the W3C OWL Working Group